In an operating room of a hospital or health care facility or other such specialized environment, air handling needs often differ from other areas of the facility. For instance, in order to reduce the risk of infection or other deleterious result, it is often desirable to have a higher level of air recirculation in an operating room than in other rooms or areas of a hospital. Indeed, there is often the requirement that the air in an operating room be recirculated a certain number of times per hour, and that the air circulated back into the room contain a specific minimum percentage of outside air. There are often filtration requirements for operating room air also. The same can be true of clean rooms in silicon wafer manufacturing and other like areas where the air needs to be more often filtered and treated than in other areas of the same facility.
Conventionally, in order to provide an increase in the air recirculation in such a specialized environment, the air handling system for the entire facility was designed so as to permit the high levels of recirculation needed for the more specialized environments within the facility. As such, the air handling system was designed to be much larger and with a much higher capacity than would normally have been required for a facility of like size. This resulted in a significant decrease in system efficiency and a substantial increase in air handling system cost.
Air handling systems for controlling air flow in an operating room have been proposed in the past. For instance, Nillson, in U.S. Pat. No. 4,781,108, proposes a system for providing clean air to an operating room which includes a central air supply source adapted to direct the air towards the operating table. Likewise, in U.S. Pat. No. 5,086,692, Welch and Bloomfield propose an air handling system for an operating room which is adapted to direct air from a diffuser in a manner which reduces concentrations of air borne bacteria and other particulates.
While the two cited patents each relate to means for directing the airflow within an operating room, neither addresses the problem of providing an increase of the recirculation of air in the operating room without over-burdening the facility air handling system.
What is needed therefore, is an air handling system for a specialized environment such as an operating room in a hospital or other health care facility, which can function to increase the circulation of air in the specialized environment without requiring an outsized air handling system.